Method of making container seals



J1me 1935- R. s. WESTGATE ETAL 2,004,964

METHOD OF MAKING CONTAINER SEALS Original Filed Jan. 11, 1928 Harry(3.65am

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Patented June 1a, 1935 UNITED STATES PATENT OFFICE 2,004,965 METHOD orMAKING con'mmna SEALS York Application January 11, 1928, Serial No.246,008

Renewed September 29, 1933 Claims. (Cl. 113-121) 5 as to be readilypierceable by an ordinary knife for making the contents instantlyavailable.

In the packaging of gases'or highly volatile liquids in sheet metalcontainers for transportation, storage, sale, and'use under aconsiderable range of thermal conditions, it is of the utmost importanceto minimize leakage at the closure and consequent contamination, waste,and danger of explosion. Sealing by means of solder has been thecommonest method of accomplishing an airtight closure, but this methodhas been attended by numerous disadvantages: among others, theappreciable cost of solder; the necessity of performing the work byhand; the hazard of applying the hot soldering iron in the presence ofthe highly inflammable gas or vapors; the difficulty of assuring theabsolute covering of the joint. a v

In an effort to avoid these disadvantages it has been proposed to effectthe seal mechanically, dispensing with the solder; but closures of thistype that haveheretofore appeared have been of such construction as tobe unable to withstand, for example, the heat of the tropics and otherrigorous conditions, and do not perform satisfactorily even in ordinarycircumstances imthe temperate zone.

It is an object of this invention to provide a mechanical seal thatshall be free from the defects of the soldered closure and shallfurthermore be inexpensive and virtually hermetic, so as to be proofagainst all adverse climatic and other unfavorable conditions, with aliberal factor of safety.

In the practice of our invention there is placed on the neck of a sheetmetal container a soft metal cap of such marginal conformation as to fitthe upper interior of the neck and having a depending flange. A flangedhard metal ring, of. similar conformation, is then superimposed upon thecap. A stationary mandrel is now set upon the ring within the neck, andrevolving rollers, caused to converge by the application of centripetalforce upon their axes, are applied to the ring flange and, by rapidlyspinning thereagainst at constantly increasing speed, gradually tightenit against the exterior of the neck, the interposed soft metal servingas a packing and forming an impervious joint. Access may thereafter behad to the contents of the container by puncturing the center of thesoft metal cap with any sharp or pointed implement, for example, a knifeor a pin, or by cutting the soft metal along the inner periphery of thehard metal ring. In contemplation of the latter procedure a suitablydimensioned inward offset is provided in the neck for seating a stopperto protect. the unused portion of the contents.

The understanding of the objects, advantages, and practice of theinvention will be facilitated by reference to the followingspecification and accompanying drawing in which Figure 1 is a plan viewof the closure cap;.

Figure 2 is a plan View of the closure ring;

Figure 3 is an elevation, partly in section, of a container with the capand the ring on its neck and of the spinning apparatus in idle position;

Figure 4 is a similar view showing the closure sealed and the spinningapparatus in operative position;

Figure 5 is an enlarged sectional view of a fragment of the sealedclosure;

Figure 6 is an elevation showing in section a sealed closure from whichthe central portion of the cap has been removed, with a stopper insertedand seated in the offset; and

-Figure 7 is an elevation showing in section a modification of thesealed closure.

In the drawing I0 designates a container, preferably of sheet metal,provided with a neck ll, preferably taper, having a shoulder I2 and ataper central offset l3. A stamped cap l4 formed of a soft metal such aslead and comprising a central circular portion l5, which may be domed ifdesired; an annular portion I6 so inclined upwardly as to fit theinterior of neck II, and a depending flange H, is set upon the neck I l.A ring 18 formed of a hard metal such as tin plate and having a generalconformation similar to that of cap I4 except that it is centrallyapertured, giving a circular inner periphery l9, and having a flange 20,is now mounted upon the cap l4.

Then the container is placed under a spinning apparatus (not a part ofthis invention) including a stationary mandrel with a head 21 conformingin shape with the interior of ring l8 and a shank 22 surrounded by arotatable hollow shaft 23 provided at its lower extremity with a flange24. The latter has a plurality of regularly spaced slots 25 (only one ofwhich is shown), each receiving a taper arm 26 the bottom of whichcarries a rotable roller 21 having a conical surface 28 and held inplace by This spinning apparatus is lowered until the stationary mandrel2| is seated in ring l8. By suitable means shaft 23 is now set inrotation. The centrifugal force thereby exerted upon the distal ends ofarms 26 gives rise to a corresponding centripetal force at the proximalends thereof, bringing conical surfaces 28 into firm contact with flange20. The speed of rotation is then steadily increased and causes aconstantly increasing pressure by surfaces 28 against flange By virtueof this accelerated rotation of shaft 23, the revolving and rotatingrollers 2! spin the flange at every point of its surface tight againstneck II, the interposed soft metal flange l1 serving as a packingthroughout its 7 area. A virtually hermetic seal is thus obtained.

Instead of they embodiment above illustrated and described, forms may beconstructed according to the same principle wherein a seal is providedinteriorly of the neck or both exteriorly and interiorly thereof. Forexample, by rollers similarly operated with and against the interior ofring l8, or by other suitable means, the interior of ring It may be spunagainst the interior of neck H, the interposed annular portion l6forming a wide, impervious seal.

To make the contents accessible it is necessary merely to punctureportion IS with a sharp or pointed implement. It is generally found,however, that all the contents are not exhausted simultaneously, and itbecomes desirable to safeguard the residue. Offset I3 is provided forthis purpose; so that when portion 15 has been removed by cutting alongperiphery I9 with a knife, for example, and part of the contents pouredout, a suitable stopper 3|, which maybe an ordinary cork, is insertedinto the offset l3,

which is of such shape as to seat the stopper -not required, andthemodification shown in Figure 7 maybe employed.

Containers formed with the closure herein described remain impervious atthe seal even though subjected-to conditions'far more rigorous thanthose encountered in transportation, storage, and use in variousclimates. For example, if filled with ether and immersed for fifteenminutes in water maintained at a temperature of 135 F., not more thanabout five per cent of the cans so sealed develop any leakage. Thisprovides a large factor of safety. whereby the probability of leakage inordinary circumstances is reduced practically to zero.

Various changes may be made in the method of sealing containers and inthe form, construction and arrangement of parts of the container withoutdeparting from the invention or sacrificing any of the advantagesthereof.

' We claim:

1. Themethod of mechanically sealing a sheet-metal container to adapt itto hold ether secure against escape, and of simultaneously providing thecontainer with a readily pierce- .able closure, which comprisessuccessively superposing upon the neck of the container a softmetal capand a hard-metal ring, each having a depending flange, and, by means ofrevolving 'and rotating rollers pressing against substantially theentire width of the ring flange, gradually spinning the flanges.concomitantly towards the neck until they are closely juxtaposedthereto, thereby tightly confining the entire circumference andsubstantially the entire width of the cap flange between the ring flangeand the neck and thus providing a vapor-impervious packing, the neck ofthe container retaining substantially its initial form and size.

2. The method of mechanically sealing a sheet-metal container to adaptit to hold ether secure against escape, and of simultaneously providingthe container with a readily pierceable closure, which comprisessuccessively superposing upon the neck of the container a soft-metal capand a hard-metal ring, each having a depending flange, and, by means ofrevolving and rotating rollers pressing against the ring flange,spinning the flanges towards the neck until they are closely juxtaposedthereto, thereby tightly confining the cap flange between the ringflange and the neck and thus providing a vapor-impervious packing.

-3. The method of mechanically sealing a sheet-metal container to adaptit to hold ether secure against escape, and of simultaneously providingthe container with a readily pierceable closure, which comprisessuccessively superposing upon the neck of the container a softmetal capand a hard-metal ring, each having a depending flange, and, by means ofrevolving and rotating rollers pressing against the ring flange,spinning the flanges towards the neck until they are closely juxtaposedthereto, thereby tightly confining the entire circumference andsubstantially the entire width of the cap flange between-the ring flangeand the neck and thus providing a vapor-impervious packing.

4. The method of mechanically sealing a sheet-metal container to adaptit to hold ether secure against escape, and of simultaneously providingthe container with a readily pierceable closure, which comprisessuccessively superposing upon the neck of the container a softmetal capand a hard-metal ring, each having a depending flange, and spinning theflanges towards the neck until they are closely juxtaposed thereto,thereby tightly confining the cap flange between the ring flange and theneck and thus providing a vapor-impervious packing,'the neck of thecontainer retaining substantially'its initial form and size.

5. The method of mechanically sealing a sheet-metal container and ofsimultaneously providing it with a-readily pierceable closure,-

RALPH S. WESTGATE. HARRY C. A. BEHR.

